摘要:

We have recently completed a monograph on the recent and fossil Hawaiian marine bivalve mollusks. This embraces 189 species and sub‐species, which belong to 105 genera and sub‐genera. Most of the fossils appear to be Pleistocene, a few may be Plioc

ISSN:0002-8606    

DOI:10.1029/TR017i001p00045

年代:1936

数据来源: WILEY

摘要:

The existence of earth‐tides has been shown by (1) studies of long‐period ocean‐tides and (2) the tilt of land‐surfaces usually measured by horizontal pendulums, and (3) by observations on the variation of gravity at a given place. The method involving the study of ocean‐tides may be dismissed as having only historical interest since any significant measurement of earthtides by this method is quite impracticable. The second method has been used extensively since horizontal pendulums or equivalent devices of adequate sensitivity for measuring the tilt of landsurfaces have long been available. However, though the required measurements may be made, the problem of interpretation in terms of vertical displacement necessarily involves the integration of many simultaneous observations covering a large area, for normal variations in the effective rigidity of the Earth's crust due to variations in lithology or structural features result in spurious local deformations which must be eliminated from the broad‐scale picture if a true measure of the vertical tidal displacement is to be obtained. Clearly, observations at an excessively large number of stations would be required and the final interpretation would present an enormous problem. Indeed, the difficulties appear quite insurmountable if one is to judge from results thus far obtained and the reports of recent work (Travaux de la Association de Géodésie, Union Géodésique et Géophysique Internationale, Rapport sur les Marées de I' Écorce Terre

ISSN:0002-8606    

DOI:10.1029/TR017i001p00046

年代:1936

数据来源: WILEY

摘要:

Geodetic field‐work was carried on during the past season, on a moderate scale, in five different provinces. In addition, a number of astronomical stations for mapping and charting purposes were established in the Canadian Eastern Arctic; while in Newfoundland several engineers of the Geodetic Survey of Canada, Department of the Interior, commenced an extensive scheme of triangulation. The latter undertaking, the result of a joint agreement between the Government of Canada and the Commission of Government of Newfoundland, marked the beginning of a field‐operation which will require five years for its complet

ISSN:0002-8606    

DOI:10.1029/TR017i001p00052

年代:1936

数据来源: WILEY

摘要:

The geodetic program of the United States Coast and Geodetic Survey, at first augmented by the increase of our regular appropriation in the year 1931 and later further increased by allotments of emergency funds, was very drastically curtailed in July, 1935, due to the exhaustion of both emergency and regular appropriations. Since that time it has been possible to continue only such field‐work as was required to smooth out some of the ragged ends, to obtain base‐measurements and astronomic observations as necessary for the adjustment of the various loops of triangulation, and to continue gravity‐work in accordance with our plan of cooperation with a number of scientists who were sponsoring this type of

ISSN:0002-8606    

DOI:10.1029/TR017i001p00056

年代:1936

数据来源: WILEY

摘要:

Geodetic triangulation—In continuing the extension of projected triangulation in the Republic, the work done in 1935 was limited to that part of the arc along the 102° meridian contained in the State of Zacatecas, with the object of basing upon it the geographic surveys which are being made in that State for the construction of its map. Observations were also continued on the projected arcs along the Lerma and Santiago rivers, with the purpose of connecting this triangulation across the states of Jalisco and Nayarit with the chain already observed in the State of Sinal

ISSN:0002-8606    

DOI:10.1029/TR017i001p00061

年代:1936

数据来源: WILEY

摘要:

That there exists a relationship between gravity‐anomalies and geologic structure has long been suggested by G. K. Gilbert, J. Barren, David White, William Bowie, and many others. White [see number 1 of “References” at end of paper] observed that negative anomalies were found over synclines, and that positive anomalies occurred over anticlines. Bowie [2]and Miller [3] both pointed out that positive anomalies were found in regions of exposed pre‐Cambrian rocks, and that negative anomalies were observed over Cenozolc se

ISSN:0002-8606    

DOI:10.1029/TR017i001p00063

年代:1936

数据来源: WILEY

摘要:

The geophysical activity in Texas and Louisiana at the present time is as follows: Seismograph crews in the Gulf Coast, 77; in east Texas, 13; in north Texas, west Texas, and southeast New Mexico, 6; total, 96. Torsion‐balance crews in the Gulf Coast, 32; in east Texas, 1; in north Texas and west Texas, 3; total, 36, Magnetometers, 7, Gravimeters, 7 (all in the Gulf Coast), pendulum crews, 3 (all in the Gulf Coast). Experimental electric crews, 2. The grant total of all types of geophysical crews is 15

ISSN:0002-8606    

DOI:10.1029/TR017i001p00076-3

年代:1936

数据来源: WILEY

摘要:

The routine work of the Coast and Geodetic Survey in seismology was quite well established by the time of the last meeting and is outlined in the report of the Section of Seismology (pp. 96–99, Transactions of 1935). Only changes and additions in this part of the work will be mentioned. The same abbreviations will be used as in that report: MIT for Massachusetts Institute of Technology; CGS for Coast and Geodetic Survey; JSA for Jesuit Seismological Association; CIW for Carnegie Institution of Washington; Cal‐Tech for California Institute of Technology; SRL for Seismological Research Laboratory; UC for University of California; NBS for National Bureau of Standa

ISSN:0002-8606    

DOI:10.1029/TR017i001p00077

年代:1936

数据来源: WILEY

摘要:

Five years ago at the Pasadena meeting of the Seismological Society the writer ventured to state in a preliminary report of the evidence for a focal depth of 400 km for the Japanese earthquake of March 29, 1928, that the occurrence of earthquakes at a depth of 400 km may well have large significance for isostasy and related problems, as well as in regard to structure, constitution, and condition of the Earth. At that time deep foci enjoyed only a modicum of scientific respectability, but since then they seem to have found an accepted place in the family of scientific data, and interest has arisen in regard to their significance and implications. The present paper is an attempt to develop, to a little extent, some of these implications.

ISSN:0002-8606    

DOI:10.1029/TR017i001p00081

年代:1936

数据来源: WILEY

摘要:

The recent research at Technology has been concentrated largely upon three important problems, none of which would offhand seem to be very difficult, but which have already consumed over two years of work and the end is not yet in sight. These are (1) the behavior of elevated water‐tanks when subjected to earthquake‐motions, (2) the development of a quake‐resistant design for such structures, (3) the development of a machine for reproducing actual earthquake‐

ISSN:0002-8606    

DOI:10.1029/TR017i001p00083

年代:1936

数据来源: WILEY